1. Field of the Invention
The present invention relates to a picture signal-processor, a picture signal processing method, and a picture signal processing program product that can compensate for color blur arising from sampling of a video signal.
2. Description of the Related Art
When a color video signal is processed, processing is performed after the color video signal has been separated into signals of red (R), green (G), and blue (B) that are standard colors. For example, when a video signal is digitized, sampling is executed for each of the picture signals of RGB at an identical sampling timing, as shown in FIG. 15, and digitization is executed using an analog-to-digital converter (A/D converter). By sampling the picture signals of the standard colors at the identical sampling time in this way, it is possible to eliminate the color blur that may occur when sampling values of all the standard colors are superimposed later and displayed.
At this time, if individual A/D converters are prepared for picture signals of RGB, respectively, it comes with problems, such as enlargement of a circuit scale of the picture signal processing circuit and increase in power consumption. Therefore, as shown in FIG. 14, generally considered is a method in which a changeover switch 10 is provided, the picture signals of RGB are changed over in turn by a control circuit 12, and the picture signal thus switched is inputted into a single A/D converter 14 and outputted therefrom in time with a predetermined phase clock Cp.
However, in the case where the picture signals of RGB are A/D converted according to the phase clock Cp by changing over the picture signals in turn, a sampling timing of each signal will be shifted by a time equal to an integer times the phase clock Cp, as shown in FIG. 16. As a result, deviation of signal intensity D arises in each picture signal (G and B) compared to that in the case where all the picture signals of RGB are sampled at an identical sampling timing. Consequently, when the picture signals of RGB are superimposed finally to perform display, it becomes a cause of producing the color blur.
The present invention has for its object the provision of a picture signal processor, a picture signal processing method, and a picture signal processing program product that compensate for the color blur of picture signals in view of the above-mentioned problem of the conventional technology.